Lift platform truck



D. s. ANDREWS E'r AL April 16, 1935.

' LIFT PLATFORM TRUCK 3 ySheets-Sheet 1 Filed June 9, 1930 Apri 16,1935. D s. ANDREWS ET AL 1,998,183

y LIFT PLATFORM TRUCK l y A Filed Jun@ 9, 195o 5 sheets-sheet 2 dof/Af/Po/MLD WHL/5 April 16, 1935- D. s. ANDREWS ETAL 1,998,183

LIFT PLATFORM TRUC K Filed June 9, 1950 3 Sheets-Sheet 3 Patented Apr.16, 1935 Y LIFT PLATFORM-TRUCK Donald S. Andrews, Rumson, N. J., andJohn Ronald Wyllie, Newy Canaan, Conn., assignors to Andrews CraneCorporation, New York, N. Y., a corporation of Delawarel ApplicationJune 9, 1930, Serial No. 460,050

12 Claims.

method of handling freight in which the goodsV to be shipped are placedin large containers having permanent supports so constructed that Whilesupported on the floor, they may be engaged by a lift-platform truck,freed from the floor and thereby transferred to the controly of thetruck, carried to any desired place-and there deposited, all Withoutmanual handling as required by present methods. The present inventionwas devised particularly for use in this method, although in some of itsfeatures it has a wider application.

The primary object of the invention is to facilitate the handling ofmerchandise in such containers by mechanical means, that is, in a Way toavoid manual handling, to the end that the loaded and unloadedcontainers may be mechanically engaged with and disengaged from thetruck, and

tainer into a confined space and deposit it therein orremove it fromsuch a space.

Another object of the invention is to effect the movement-of loads in anefficient manner over irregular surfaces such as are encountered atfreight depots and docks, for example, where the load must be moved`over an upwardly or downwardly inclined ramp.

`Another object of the invention is to provide 4-0 beneath a containerwhen it is approached from an angle to a horizontal` plane orl from anangle to a vertical plane.

Another object of the invention is tov so relate means as to prevent theload from decreasing the tractive effort of the driving means. Y

Another object of the invention is to facilitate effective control ofthe apparatus by the operator.

The invention consists in the means hereinafter described andillustrated in the annexed drawings, and particularly set forth in theclaims.

The invention is capable of embodiment ina wide variety of forms but thebest forms in which We have contemplated applying the principles thetruck may be manipulated to move the con-y means whereby a lift-platformmay be projected the power driving means and the load-carryingV thereofare shown in the accompanying drawings' in which,

Fig. l is a side elevation of the preferred form of truck, with thefront end of the trailer member broken away.

Fig. 2 is a top plan View thereof..

Fig. 2ca'is-a top plan View of the tapered front end. of thelift-platform.

Fig. 3' is a vertical section of the trailer member of the truck;showing a lift-platform and mechanism for elevating it.

Fig. 4 is a diagrammatic plan View of the tractor member of the truck intwo positions, illu-strating a characteristic kmovement of the drawbarof the truck.

i Fig. 5 is an enlarged fragmentary section of the draw-bar connectionwith the trailer, taken on line 5-5 of Fig. 2.

Fig. 6 is a perspective view of a loaded platform for the handling ofwhich, or structures of the same general characteristics, this inventionisV designed. v

Fig. 'l illustrates, inplan, a box car partially loaded and in thecourse of loading, illustrating the utility of one of the features ofthe truck.

Fig. 8 is a fragmentary plan view illustrating how the trailer member ofthe-truck may be inserted beneath a loaded container while in a confinedspace in a box car.

tainer from a box car after the container has been raised from the flooronto the lift-platform. Fig. 10 is a view similar to Fig. 9 illustratingtwo nal stepsof manipulating a loaded container before removing it froma car.

Fig. 11 is a side elevation of a tractor member slightly modified as tothe construction of the draw-bar in respect to its connection with thetractor member, and with a couplingv means adapted to be connected withan eye on the adjacent end of a wheeled container or with such an eyemounted on the rear end of the trailer member shown in Figures 1 and 3.

Figs. 12 and 13 are diagrammatic views illustrating the utility ofcertain features of the trailer member, and the relation thereof to thetractor.

Our invention is designed for use inhandling freight by a containersystem, `adapted to the present railroad equipment including box carshaving a floor width of from 8 feet to 8feet 6 inches with `50 had beendevised or attempted in which present g;

Fig. 9 illustrates two steps in unloading acon- 30 railroad equipmentwas utilized. For the most successful operation of such a system thecontainers should be large and of a size such that a certain number ofunits will substantially ll the floor space of a box car. It will beappreciated that Where large containers are employed of a size that aplurality will fill substantially the entire floorspace of a box"car,the relatively small spaces available for manipulating them into placeby purely mechanical means presents a very difficult problem, and priorto our invention there was no apparatus devised, lso far as we havediscovered, which could be used to place such containers or remove themfrom the restricted space contemplated by us. Prime requisites of atruck which will operate successfully to perform the described functionis that it shall be able to move the container on an axis within itself,and that it shall be able to impart considerable movement to thecontainer under its control with only slighty bodily motion of itself.

This application is a continuation in part of our application Serial No.197,033, filed June 7, 1927.

We have devised a number of embodiments to effect the desired movementsof lthe containers, but the form now to be described is, soffar as Wehave discovered up to the present'time, the most efficient. We willfirst set out the exact construction and dimensions of this embodiment,and then point out the considerations which would govern departures fromsuch construction and dimensions.

Referring to the drawings in detail, the truck is composed of a tractormember I, and a trailer member 2, articulated to the tractor member. Thetractor member comprises a frame 3 of a Width of approximately 3 feet 6inches and of a length approximately 5 feet. This frame is supported atits front end by two traction wheels 4, 4', which are preferably fixedon axles having interposed differential mechanism of any desired form.The rear end of the tractor frame is supported by a single steeringwheel 5 mounted for steering movement about a vertical axis through an.arc not less than about 170. The axis of the steering Wheel isapproximately 3 feet from the axis of the traction wheels, and the rearend of the tractor frame extends approximately 1 foot to the rear of theaxis of the steering wheel,

The tractor frame carries a tiller'handle 6 to give steering movement tothe steering wheel, and is provided with the usual means appurtenant toa tractor including means for furnishing motive power. A suitableplatform 'I, adapted to support an operator, is connected with the frontend of the frame 3, the location of this platform being selected forreasons hereinafter stated. A draw-bar 8 is connected with and extendsforwardly from the front end of the frame 3, the connection beingpreferably a pivotal connection on a horizontal axis by means of a bolt9 passing through brackets I0, connected rigidly with the frame, andthrough the bifurcations II of the rear end of the draw-bar, so that thedraw-bar is rigid in a horizontal plane but Iis capable of pivotalmotion in a vertical plane@v The front end of the draw-bar is providedwith means complemental to means on the'trailer member for -coupling thetrailer member and tractor member together, such complemental meansbeing hereinafter referred to as'coupling means'. A The length of thedraw-bar in this embodiment is such that the coupling means isapproximately 6 feet from theaxis of the traction wheels.

The trailer member 2 comprises a frame I2, preferably of the same widthas the tractor frame and about 6 feet in overall length, supported byrolling-supporting means which may take various forms and the elementsof which may be variously related to each other and to the frame. Asillustrated, such rolling-supporting means comprises load-supportingwheels I3 mounted on a horizontal axis onV opposite sides of thelongitudinal axis of the frame, such load-supporting wheels being placedso that when a container is mounted thereon they will be substantiallyunderneath, or slightly rearward, of the center of the load; foracontainer of the size contemplated by us the location of the axis of theload-supporting wheels would be approximately 4 feet from the rear endof the trailer frame. The rear end of the trailer frame is supported bytwo casters I4 arranged on opposite sides of the longitudinal axis ofthe trailer frame, which permit the tractor member to push land pullythe trailer, and also to swing it laterally on the load-supi portingwheels, the casters conforming to any motion imposed upon the trailer.'A single caster I5 is mounted in the extreme' front end of the trailerframe in substantially the longitudinal .axis thereof. Preferably theelements of the rolling-supporting means are so related that, when on alevel surface, the trailer'will be supported by the load-supportingwheelsy and casters I4, i

or by the load-supporting wheels and caster I5 (see Fig. 3)'vthis beingeffected by so mounting the caster I5 that the lower periphery is abovea plane tangent to the load-supporting wheels I3 and the rcasters I4 attheir points of Contact with the supporting surface, as clearlyindicated in Fig. 3.V A

The trailer frame supports va lift-platform I6 mounted for verticalmovement thereon, such vertical movement being effected by wellvknownmeans. As shown, the construction which enables the platform to beelevated consists of cam plates I1 depending from theplatform, which areengaged by rollers I8 mounted on a longitudinally movable actuatingframe I9, which is reciprocated'by an electric or other suitable motor20, under control of the operatorfrom his position on the platform `I.'I'he actuating frame is controlled through the medium'of a thrust screw2I connected to the actuating frame, which is extended and retracted bymeans of suitable gearing operated by the motor, all of which is oldinthe art. l

The sides of the frame of the trailer member at the front end aretapered and the sides of the' lift-platform are correspondingly taperedas indicated at 22, Fig. 2a. tapering the lift-platform is to enable itto be inserted beneath a platform container, as clearly indicated inFig. 8. lIfhe extent of this tapering will therefore be governed by theparticular conditions under which the device is used. As shownherein thelength of the tapered side is more than three-fourths of the width ofthe lift-platform, and the angular relation of such tapered sides to thelongitudinal axis of the trailer member is less than 30. The end of thetapered portion of the lift-platform is beveled downwardly as indicatedat 23, the beveled portion, as shown, extending more than a foot fromthe end of the frame. The rear edge of the trailer frame is providedwi'th an upstanding' flange or shoulder 24 adapted to`be engagedby theend of the container to' prevent its further movement rear-r -wardly. r

The purpose of thus about el inches wide, and of any height less than vAs above stated the. front end of the draw-bar 8- is coupled with'therear end of the trailer member, the -coupling shown consisting -of aball connected with the trailer which enters a .socket formed at the endof the draw-bar as clearly shown in Fig. 5. As shown in Fig. 11 thecoupling consists oi a hook on .the end ofthe drawb'ar entering ane'yeontthe member tobe. connected'thereto. Both of these connectionsprovideva universal joint; The best embodiment of the inventioncontemplates that the pivotal connection between theend of the\drawbarand the` trailer member shall be so located that the drawbar. may, inone extreme position, lie at an angle .less than `90" -to thelongitudinal axis of the This extreme position is illustrated in,

trailer. Fig;-"7,.and the. purpose thereof will be hereinafterdescribed/In order to securethis relation in the embodiment shown inFigs. l to 3, the cou- 1pling meansvof the draw-bar and the 'trailer 1.inV Fig. 4. In' the construction shown the center about which thetractor turns when the steering wheel is set for turning movement is theintersection of a line extended through the axis of the traction-wheelsand aline extended through the axis of the steering wheel at thatparticularV setting. When the steeringy wheel isset to give theVsharpest turnv to the tractor `member, the center about which4 the endof the draw-bar swings is in `lineiwith the axis of the traction 'wheelsjust outside one ofthe traction wheels,

which results in the movement of the coupling means ofthe draw-bar on anarc y whose radius is Hence it will be appreciated that the turning axisof the traction member ranges between innity (that is, movement in astraight line forwardly or backwardly), and points just outside or" thetraction wheels, so that the coupling member at theV end of the draw-barmay be caused to movey forwardly or backwardly, or to describe an arcabout any centerron either side of the frameranging between infinity(when the steering means is set for the frame to move in a straight linealong vits ,longitudinal axis) and.

points near the Vsides of the frame; in other words, they tractionmember may move 'inl a, straight line or any arc between one of greatradius and a very short radius. When the stee ing wheel is set for theminimum turning radius the coupling means will move in an arc whoseradius is greater than 6 feet, and the frame of the tractor member willswing about a point just outside one of the traction wheels, so thatthere is lateral motion of the frame with very slight longitudinalmotion thereof.

Our invention contemplates the use primarily, of containers supported onan inverted U-shaped platform of well known form, illustrated in Fig. 6,consisting of a central base and side supports or flangesby which thecontainer is supported above the floor to permit the entrancetherebeneath of a liitfplatiorm whereby, onelevating the platform, .theload is transferred from the floor to the truck. The sizeV oi thecontainer adapted for use with our trucks may be varied, but we preferto employ containers` as large as possible,V which may beused tosubstantially i'ill the floorspace of an ordinary box car with aplurality thereof and which it is possible tov pass through the doorsthereof and manipulate into place by mechanical .means thisfsizevbeingyabout 9,0l inches long and the height ofthe door openings,4 tenofwhich will occupy substantially the entire oor area ofa box car.Suchicontainers, when loaded, may

weigh upwards of iivetons. Four of such con` tainers may be placed ineither end of a box car,r

and two in the center of the car, transversely thereof, facing the dooropening. It is avery simple matter to remove the two containerslfacingthe door opening,-and little diiricultyis ex perienced in placing 'orremoving the twocontainers in the ends of the car. But the insertion orremoval of the other four containers Yin the spaces just inside thedoor, by mechanical means,

presents a very diiiicult problem, requiring theV rotation oi thecontainer atone time on an axis within itself, and at another time a'movement considerable distance.

willnow be set out in an explanation of the steps required in removing acontainer c from a-box` car (see Figs. 8,79, and l0) while containers a,b, d, e, f, g, and h remain place. f

` Operation-In the operation of removing container c from the car, theoperatorl directs the iront end of the trailer to a position oppositethe end of the container and then sets the steering wheel 5 to give thetractor member a sharp turning radius which moves the trailer in a widearc, causing the front tapered end thereof first to pass between thesupports of the container, whereupon further movement will cause thelift-platform-to move beneath the container until the flange 2'4 engagesthe end of the container. vThe lift-plat-v form is then operated to liftthe containerfree of the iioor. The steering'wheel is then set to causethe tractor member to move from the position shown in fulllines of Fig.9 to vthe positionshown in dotted lines. It may be observed from the twopositions shown that, because of the long draw-bar 'and short turningradius of the tractor, member the container may be moved into theopening between the doors in a straight line so as to avoid being jammedbetween the adjacent container OZ' and the side' ofthe car, while at thesame time the rear end of the tractor frame has moved almost laterallyinto' the door opening, thus avoiding contactwith thecontainer f and theedge of thedoor opening. The swinging motion of the tractor member iscontinuedrin theY same general direction until the parts reach theposition shown in iull lines in Fig. 10. The steering wheel is thenoperated 'to cause turning mo-A meanwhile being turned so that, asV thevinner rear corner of the container approachesfclosely to the side ofcontainer c and the outer side of container d has come nearly inlcontactwith the edge of the door opening, the axis of thedrawbar'approache's a position sharply-at anA angle to the longitudinalaxis of the trailer member.

When it has arrived at this position, the steering wheel is suddenlyturned in the opposite direction, ie., to the left, so that the Lturningaxis lly is very near the left-hand side of the tractor frame. Thetractive effort of the traction wheels then causes the end of the longdraw-bar to swing about said axis, and the length of the draw-bar issuch that there is no substantial forward motion of the container andthe containeris rotated on the load-supporting wheels I3 until thelongitudinal axis of the container is alined with the side of the car,whereupon, by reversing the position of the steering wheel 5, thecontainer may be moved into the space between container c and the sideof the car. If desirable or necessary, by properly steering the tractormember, the draw-bar may be caused to take a position at right-angles(or less than a rightangle) to the longitudinal axis of the trailermember when the container d is jammed between container c and the edgeof the door opening, as when the rear inner end ofthe container has comeinto contact with the side of container c and the outer side of thecontainer d has come into engagement with the side of the door opening,as shown in Fig. 7, whereupon, a direct forward motion of the tractormember will rotate the container, break the jam, and aline it with thespace into whichA it is to be placed. Thereafter, proper steeringmovement of the tractor member will move the container into the desiredplace. These movements are possible because of the very short turningradius of the tractor member, and the flat arc described by the end ofthe long draw-bar.

As above indicated, it is desirable that the construction of the partsbe such that, at certain times, the draw-bar shall be permitted to lie,in relation to the longitudinal axis of the trailer, at an angle of onlya little greater than 90, or even less. In the forni above describedthis may beraccornplished by a narrow draw-bar coupled to the trailer ata suitable distance from the rear of the trailer frame. It might also beaccomplished by so arranging the trailer frame with respect to thedraw-bar that the trailer frame would, in part, overlie the draw-bar inextreme position, in which case a narrow drawbar would not be required.

The purpose of placing the operators stand or platform 1 at the front ofthe tractor member is to enable the operator to more readily senselateral motion of the tractor member and observe the eifect of hismanipulation.

The purpose of tapering the front end of the trailer has already beenstated. The purpose of the downward bevel of the tapered position is toenable the trailer to be projected beneath a container when approachedat an angle to a horizontal plane, as indicated in Fig. 13.

Figs. 12 .and 13 illustrate the utility of the particular form ofrolling supporting means for the trailer above described. The floor orground overwhich such loads must be moved often have depressions orangularly related surfaces. For example, at tidewater, loads must bemoved from dock to ship and vice versa, up and down ramps which arevariously inclined to the floors of the dock and ship, and notuncommonly containers are supported at the upper edge of an inclinedramp, as illustrated in these figures. Where a horizontal surface thusmeets an inclined surface serious difculties are encountered with trucksof ordinary construction. One such difficulty is that in passing up aninclined ramp, especially one sharply inclined, the forward end of thetruck or the container thereon will eni gage the ramp and stop furthermovement.V This difliculty'is entirely avoided b'y providing a roller,.such as caster I4, at the forward end of the truck, which engages theinclined surface; and this feature is especially applicable tolift-platform trucks now in general use as well asto the trailer memberldisclosed herein, and greatly increases their utility.

The caster I5 has an additional important functionl when used incombination .with the two rear casters I4, which together provide astable supportfor the trailer and its load while moving onto an inclinedsurface and while the central supporting wheels are lifted clear of thesupporting surface, as clearlyshown in Fig. 12. vIn use, surfaceconditions will vary greatly, but the rolling supporting means hereindisclosed provides stable support for the trailer at'not less than threepoints under all conditions.

Another feature of the rolling supporting means used for the trailer,when employed withv a draw-bar pivoted to the tractor on a horizontalaxis, is that the load is always supported on the trailer alone, orindependently of the tractor, thus removing all strain from the tractorand preventing all interference with its tractive effort.

' Fig. 11 shows a modification of the draw-barl connection with thetractor frame in that the bifurcations of the rear end of the draw-barare morewidely separated and are pivoted to the outer faces of thetractor frame, as indicated at 25, with a View to increasing thestrength of the connection between ydraw-bar and tractor frame in alateral direction. This figure illustrates another modification of ourinvention in which containers having permanent rolling-supporting meansare adapted to co-operate with the tractor member, and a trailer memberis dispensed with, the rolling-supporting means for the containerconsisting of centrally arranged load-supportingwheels and casters atopposite ends, similar to the arrangement of the rolling-supportingmeans on the trailer.

In both of the embodiments of the tractor member illustrated, thetraction wheels are not adapted to be steered, for which reason thecenter of the shortest turning radius is outside the traction wheels. Itis obvious that these traction wheels might be constructed for steeringmovement in which case the center of the shortest turning radius mightbe brought to a point within the boundaries of the tractor frame.

The specific embodiment of our invention 'described is designed to meetthe special situation presented by the ordinary box car used in presentrailroad equipment. It is therefore obvious that if more space isavailable for manipulation the special features described may bemodified in various ways,in the character of the traction means and thesteering means and their relation to each other, the length of thetractor and trailer frames and length of the draw-bar. The principalcharacteristics of a device which will perform the required functionsinvolve a tractor member having a comparatively long draw-bar withsteering means that will give aV wide sweep to the coupling means at theend of the drawbar compared to the bodily motion of the tractor frame,with the capacity to swing the container on axes within the boundariesof the trailer frame. scribed the draw-bar is of such length that thedistance of its coupling means at the free end from the axis of thetraction wheels is approximately twice the length of the wheel base,useful results are obtained when this distance is ap- While lin thepreferred form above de- "What we claim is:

l. A warehouse tractor member comprising a frame, traction wheels,mounted near the front end of .the frame, ydirigible rolling supportingmeans near the rear end of the frame andfsteering thenefcrl adapted togive directed movement to the rear end of the frame along thelongitudinal axis of the frame or at any angle thereto up toapproximately 50 on either side of said longitudinal axis, and adraw-bar connected to and extending forwardly from said frame and havingcoupling means at its free end, the length of the draw-bar being suchthat the distance of the coupling means from the axis of the tractionwheels is greater than the distance of said axis from the rear end ofthe frame.

2. A warehouse tractor member comprising a frame, traction wheelssupporting the front end of the frame, a steering wheel supporting therear end of the frame adapted to turn through an angle of at least so asto give directed movement to the frame in directions ranging between aright line along the longitudinal axis of the frame to 50 on either sideof said axis, the distance between the axis of the traction wheels andthe axis of the steering wheel being approximately three `feet, and adraw-bar connected to and extending forwardly from the frame and havinga coupling at its free end of such length that the distance of thecoupling from the axis of ther traction wheels is approximately twicethe wheel base.

3. A warehouse tractor member comprising a frame, rohing supportingmeans for the front and rear ends of the frame including tractionwheels, a draw-bar rigid with the frame in a horizontal plane andextending Yforwardly therefrom and having coupling means at its freeend, the length of the draw-bar being such that the distance of thecoupling means from the axis of the forward rolling supporting means isapproximately not more than two times, and not less than one andone-half times, the length of the wheel base, and means connected withthe rolling supporting means to control the movement of the tractormember, whereby the coupling means may be caused to move forwardly orbackwardly or to describe an arc about any center on either side of theframe ranging between infinity and points near the sides of the frame.

4. A warehouse tractor member comprising a frame, traction wheelssupporting the front end of the frame, and dirigible rolling supportingmeans supporting the rear end of the frame, a draw-bar rigid with theframe in a horizontal plane extending forwardly therefrom and havingcoupling means at its free end, the length of the draw-bar being suchthat the distance of the coupling means from the axis of the tractionwheels is more than one and one-half times the length of the wheelbase,and means connected with the dirigible rolling supporting means tocontrol the movement of the tractor member, whereby the coupling meansmay be caused to move forwardly or backwardly or to describe an arcabout any center on either side of the frame ranging between innity andpoints near the sides of the frame. I

5. A warehouse tractor member comprising a frame, traction wheelssupporting the front end of the frame, a single steering wheelsupporting v the rear end of the frame, a draw-bar rigid with the framein a'horizontal plane extending forwardly therefrom and having couplingmeans at its free end, the length of the draw-bar being such that thedistance of the coupling means from the axis of the traction wheels ismore than one and one-half times the length of the Vwheel base, andmeans connected with the steering wheel .to control the movement of thetractor member, whereby the coupling means may be caused to moveforwardly or backwardly. or to describe an-arc about any center oneither side of the frame ranging between infinity and points near thesides of the frame. l

6. The combination specied in claim 5 in which the axes of the tractionand steering wheels are approximately three feet apart.

7. The combination specified in claim 5 in which the traction frameextends approximately one foot forwardly and rearwardly beyond the axesof the traction and steering wheels.

8. A warehouse tractor member comprising a frame, traction wheelssupporting the front end of the frame, a draw-bar connected to andextending forwardly from the frame and having coupling means at its freeend of such length that the distance from the coupling means to the axisof the traction wheels is greater than the distance between said axisand the rear end of the frame, and dirigible rolling supporting meanssupporting the rear end of the frame with controlling means thereforwhereby the coupling means may be caused to move forwardly or backwardlyalong the longitudinal axis of the frame or to describe an arc about anycenter on either side of the frame ranging between innity and pointsnear the sides of the frame.

9. In a lift-platform truck, a tractor member having traction wheels atits front Vend and dirigible rolling supporting means at its rear end, adraw-bar attached to the tractor member and extending forwardlytherefrom, a trailer member having a lift-platform, a pivotal connectionbetween the forward end of the draw-bar and the.

rear end of the tractor member devoid of substantial lost motion in adirection at right-angles to the draw-bar, load-supporting wheelsintermediate the ends of the trailer member and rolling supporting meansat the rear end thereof adapted to conform to any movement imposed uponit by the tractor member through the draw-bar, the length of thedraw-bar from the axis of the traction wheels to its pivotal connectionwith the trailer member being greater than the wheel base of the tractormember.

10. A trailer member for a truck, comprising a frame having a centrallyarranged coupling eye at its rear end, load-supporting wheelsintermediate its ends and casters supporting the rear end, and alift-platform mounted on the frame tapered at its front end, the lengthof the tapered sides being more than three-fifths of the width of theframe and arranged at an angle to the longitudinal axis of the trailerframe of between 20"y and 50. i

11. A trailer member for a truck comprising a frameA having a couplingmeans at its rear end, load supporting wheels intermediate its ends,rolling supporting means for the rear end of the frame, and alift-platform mounted on said frame having its front end tapereddownwardly.

l2. In a lift-platform truck, a tractor member having traction wheels atits front end and dirigible rolling supporting means at its rear end, adraw-bar attached to the tractor member and extending forwardlytherefrom, a trailer member having a lift-platform, a pivotal connectionbetween the forward end of the draw-bar and the rear end of the trailermember devoid of substantial lost-motion in a direction at right anglesto the draw-bar, the length of the draw-bar being such that the distanceof its pivotal connection with the trailer member from the axis of thetraction wheels is greater than the distance between the axis of thetraction wheels 10 and the rear end of the tractor frame,load-supporting wheels intermediate the ends of the trailer member, androlling supporting means at the rear end of the trailer member adaptedto conform to any movement in a horizontal plane imposed upon it by thetractor member, whereby the tractor member may pull or push the trailermember or swing it laterally while it is supporting a load.

DONALD S. ANDREWS.

JOHN RONALD WYLLIE.

